Immunomodulatory effects of anesthetics in obese patients

Abstract

Anesthesia and surgery have an impact on inflammatory responses, which influences perioperative homeostasis. Inhalational and intravenous anesthesia can alter immune-system homeostasis through multiple processes that include activation of immune cells (such as monocytes, neutrophils, and specific tissue macrophages) with release of pro- or anti-inflammatory interleukins, upregulation of cell adhesion molecules, and overproduction of oxidative radicals. The response depends on the timing of anesthesia, anesthetic agents used, and mechanisms involved in the development of inflammation or immunosuppression. Obese patients are at increased risk for chronic diseases and may have the metabolic syndrome, which features insulin resistance and chronic low-grade inflammation. Evidence has shown that obesity has adverse impacts on surgical outcome, and that immune cells play an important role in this process. Understanding the effects of anesthetics on immune-system cells in obese patients is important to support proper selection of anesthetic agents, which may affect postoperative outcomes. This review article aims to integrate current knowledge regarding the effects of commonly used anesthetic agents on the lungs and immune response with the underlying immunology of obesity. Additionally, it identifies knowledge gaps for future research to guide optimal selection of anesthetic agents for obese patients from an immunomodulatory standpoint.

Intraoperative immunomodulatory effects of sevoflurane versus total intravenous anesthesia with propofol in bariatric surgery (the OBESITA trial): study protocol for a randomized controlled pilot trial

“…Immunomodulation may have a beneficial effect, since suppression of the exacerbated inflammatory response can avoid damage such as that caused by acute inflammation [90], or a deleterious effect, since it can prevent the body from neutralizing infectious pathogens. It is now known that anesthetic agents may compromise or enhance immune function [5].…”

“…Caution is required when choosing anesthetic agents for administration in morbidly obese patients, since these drugs may influence immune function and the inflammatory process [5]. In this context, anesthetics may interact with the perioperative inflammatory response, affecting the release of cytokines [6], the expression of cytokine receptors [7], phagocytic or cytotoxic action [8], and the transcription or translation of protein mediators [9, 10], resulting in potential beneficial or deleterious effects.…”

A comparison of opioid-containing anesthesia versus opioid-free anesthesia using the Cortínez-Sepúlveda model on differential cytokine responses in patients undergoing gastric bypass surgery: a randomized controlled trial

“…However, the interindividual variability of adipose tissue distribution and the presence of comorbidities, increase the risk of surgical complications in these patients. Therefore, perioperative care and the type of anesthesia represent a great challenge for obese patients [4]. Although efforts have been made to develop standardized guidelines or protocols for anesthetic care in patients with obesity [5], an ideal anesthesia technique or drug combination are still unknown [4].…”

“…Therefore, perioperative care and the type of anesthesia represent a great challenge for obese patients [4]. Although efforts have been made to develop standardized guidelines or protocols for anesthetic care in patients with obesity [5], an ideal anesthesia technique or drug combination are still unknown [4].…”

Controversies when using mechanical ventilation in obese patients with and without acute distress respiratory syndrome

“…Obesity is associated with a chronic low-grade inflammation which may affect several organs [7]. Additionally, mechanical ventilation (MV) itself can induce and amplify lung inflammation [8,9]. Further, obese patients show unique physiology which may affect the presentation and pathophysiology of ARDS, posing specific management challenges.…”